Truss Tower Leg Reinforcing System

ABSTRACT

A reinforced triangular truss column having two vertical pipe reinforcing columns added to the three rods of the truss column is provided. Also provided is a method of reinforcing triangular truss columns comprising adding two vertical pipe reinforcing columns to a triangular truss column.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. provisional application60/829,451, filed Oct. 13, 2006, which is hereby incorporated byreference herein.

BACKGROUND OF THE INVENTION

Several communication tower manufacturers construct triangularself-supporting towers utilizing vertical columns constructed oftriangular trusses. These tower columns (often referred to as the towerlegs) resemble miniature triangular shop-welded tower sections. Whenadditional loads are added to the tower, these truss legs may no longerbe adequate to safely support the calculated tensile or compressiveloads. To alleviate this overstress, the structural capacity of thetruss columns must be enhanced. Field welding additional steel ontothese truss legs is expensive and creates the potential for severalproblems. The heat of the welding operation destroys the galvanizedcoating on the existing steel members creating a corrosion problem. Theheat of the welding operation may warp the existing steel and the sparkscreate a fire hazard. This invention was developed to address theseproblems.

SUMMARY OF THE INVENTION

Provided is a method of reinforcing a triangular truss columncomprising: providing two generally vertical pipe reinforcing columnseach having a first pipe reinforcing plate attached at the top of thecolumn and a second pipe reinforcing plate at the bottom of the column;attaching the first pipe reinforcement plate to a first existing plateof the triangular truss column; attaching the second pipe reinforcementplate to a second existing plate of the triangular truss column; andconnecting each vertical pipe reinforcing column to the truss column atone or more connection points along the pipe reinforcing column length.Also provided is a reinforced triangular truss column having twogenerally vertical pipe reinforcing columns attached to the outside of aportion of a triangular truss column.

The pipe reinforcing columns are connected to the truss column in thevertical direction using any suitable means as known in the art withoutundue experimentation. Some examples are described and shown herein. Asone example, a metal strap or band that spans one side of the triangulartruss column is connected to two legs of the triangular truss column.The strap or band may be connected to the legs of the triangular trusscolumn using any suitable means, including bolts. The band or strap isany suitable width and thickness that provides the desired amount ofsupport. It is not necessary, and is not preferred, that the metal strapbe so wide that that it results in wind resistance or excess weight. Inanother embodiment, the pipe reinforcing columns are connected to thetruss column using a band or strap which surrounds the truss column andthe pipe reinforcing columns.

In one embodiment, the pipe reinforcing plates are attached to theexisting plate of the triangular truss column using bolts. The pipereinforcing column may be made from any suitable material, and do notneed to be made from the same material. Each pipe reinforcing column maybe hollow or solid.

As used herein, “generally vertical” or “generally horizontal” indicatesthe direction does not need to be exactly vertical or exactly horizontalwith respect to a fixed point, but includes those situations where thereis a small amount of variance, for example, ±10 degrees of variance.Other degrees of variance are included, for example ±5, ±15 and ±20 andall intermediate ranges and values therein.

BRIEF DESCRIPTION OF THE FIGURE

FIG. 1 shows one embodiment of the invention in three views.

DETAILED DESCRIPTION OF THE INVENTION Truss Columns

A single truss column is constructed of three individual solid roundbars shop-welded at the top and bottom to a common plate. These threesolid bars are connected to each other with horizontal and diagonalbracing forming a three-dimensional triangular truss. It requires threetruss columns to form a single triangular tower section. These towersections are then stacked vertically and bolted together at the trusscolumn plates.

Solution:

Presented here is a method to enhance the structural capacity of theexisting truss columns that does not require field welding. Two verticalpipes are added to the three solid round rods of the truss column. Thesepipes have plates welded at the top and bottom. Several of the existingtruss column splice bolts are removed. A new pipe column is insertedwith new longer splice bolts inserted to connect the top and bottomplates of the new pipe column to the top and bottom plates of the trusscolumn. There are also straps or other devices that connect the new pipecolumn to the truss column at intermediate intervals to prevent the pipecolumn from buckling away from the existing truss column. These strapsare connected to the truss column with U-bolts or other suitableconnecting means, as known in the art. This invention is useful for anytowers with truss-type legs (columns).

The result is that the truss column is no longer comprised of just threesolid round rods but is now is comprised of the original three solidround rods plus two round pipes which may be hollow.

FIG. 1 shows one embodiment of the invention. Elevation 1 shows alarge-scale view. Elevation 1 shows two sections, section 2 and section3, also shown in FIG. 1. Section 2 shows the use of the invention at theexisting tower leg splice plate, as described herein. Section 3 shows anintermediate brace, as described herein.

All elements of the invention may be made from any suitable material, asknown to one of ordinary skill in the art. The materials used may dependon the environment where the tower is used, as known in the art. Thediameters of the vertical pipes may vary, depending on the application.The vertical pipes may be made from any suitable material, as known toone of ordinary skill in the art. The vertical pipes may be metal,composite or polymer, for example. The vertical pipes may be hollow orsolid. The connecting bands may be constructed from any suitablematerial, as known to one of ordinary skill in the art.

Although the invention is described with respect to triangular trusstowers, it is well known in the art that the invention may be used withfour-legged towers, as well, without undue experimentation, using two,three, or four vertical pipe reinforcing columns, using the informationprovided here and that information known in the art.

It should be understood that although the present description has beendisclosed by specific embodiments and optional features, modificationand variation of the concepts herein disclosed may be resorted to bythose skilled in the art, and that such modifications and variations areconsidered to be within the scope of this invention.

1. A method of reinforcing a triangular truss column comprising:providing two generally vertical pipe reinforcing columns each having afirst pipe reinforcing plate attached at the top of the column and asecond pipe reinforcing plate at the bottom of the column; attaching thefirst pipe reinforcement plate to a first existing plate of thetriangular truss column; attaching the second pipe reinforcement plateto a second existing plate of the triangular truss column; connectingeach vertical pipe reinforcing column to the truss column at one or moreconnection points along the pipe reinforcing column length.
 2. Themethod of claim 1, wherein the pipe reinforcing columns are connected tothe truss column using a band which surrounds the truss column and thepipe reinforcing columns.
 3. The method of claim 2, wherein the band isattached to the outside of the truss column.
 4. The method of claim 2,wherein the band is metal.
 5. The method of claim 2, wherein the band isbolted to one or more legs of the truss column.
 6. The method of claim1, wherein the pipe reinforcing columns are each connected to the trusscolumn using a strap which is bolted to two legs of the truss column andspans one side of the triangular truss column.
 7. The method of claim 1,wherein the pipe reinforcing plates are attached to the existing plateof the triangular truss column using bolts.
 8. The method of claim 1,wherein a pipe reinforcing column is hollow.
 9. The method of claim 1,wherein a pipe reinforcing column is solid.
 10. A reinforced triangulartruss column comprising: a triangular truss column having three trusslegs which attach together through leg splice plates, said triangulartruss column having reinforcing columns along at least a portion of twosides of the triangular truss column, the top and bottom of eachreinforcing column attached to the triangular truss column in thehorizontal direction through a top pipe reinforcing plate and a bottompipe reinforcing plate, and the reinforcing columns attached to thetriangular truss column in the vertical direction with a generallyhorizontal band.
 11. The column of claim 10, wherein the top and bottompipe reinforcing plate are each bolted to a leg splice plate of thetriangular truss column.
 12. The column of claim 10, wherein eachreinforcing column is attached to the triangular truss column with ametal strap which spans a side of the triangular truss column and whichmetal strap is bolted to two truss legs.